1. Field of the Invention
The invention refers to a dimmed motor vehicle headlight with an ellipsoidal reflector, where a light source is disposed at a first focal point of the reflector and a collector lens is disposed behind the second focal point and is supported by an annular part of a frame connected to the reflector.
2. Brief Description of the Background of the Invention Including Prior Art
A motor vehicle headlight generally comprises an adjustable diaphragm that substantially generates with its upper horizontally running edge a light-dark boundary for the outcoming light. This construction is associated with the advantage that the diaphragm edge generating the lightdark boundary can be adjusted to be located exactly at the focal points of the collector lens, since the focal point of the collector lens is situated in a large tolerance region.
Such a dimmed motor vehicle headlight is known from the German Petit Patent DE-GM No. 84 30 629. The frame and the diaphragm according to this teaching are provided as two parts, and they are made by a die casting process. The frame has the shape of a table and connects the reflector and the collector lens solidly to a single unit. The diaphragm is shiftably guided in the direction of the optical axis by two legs of the table, and after the adjustment of the diaphragm, it is fixed in position by screws at the legs of the table. The adjusting mounting of the diaphragm as taught in the reference is complicated and cumbersome in the mass production of articles and is too expensive in view of high labor costs. In addition, improper storage and mounting of the diaphragm can result in damage to the diaphragm edge. It is a further disadvantage that the diaphragm and the frame are produced in separate machines and according to a relatively expensive die casting method.
This reference teaches that the collector lens is inserted from below into an opening of the upper side of the frame and lies with its outer flange at the edge of the opening. The attachment of the collector lens at the frame can be achieved by adhesive methods or by spring sheet metal which rests against the outer flange under pretension. The spring sheet metal can be solidly riveted or screwed to the frame. The insertion of the collector lens between the legs into an opening of the frame and the attachment of the collector lens by adhesive gluing, riveting and screwing is cumbersome and time consuming. In addition, if the frame is damaged, the collector lens cannot be demounted since it is attached by riveting or gluing. In the case of a screw connection, a safe fixed position of the collector lens is not always assured.